Valve.



JAMES GARVIE, OF CLEVELAND, TRANSVAAL.

. VALVE Specification of Letters Patent.

Patented Dec. 21, 1909.

Application filed'April 19, 1909. Serial No. 490,737.

To all whom it may concern:

Be it known that I, JAMES Ganvrn, a subject of the King of Great Britain, and resident of Cleveland, Transvaal, have invented certain new and useful Improvements in Valves, of which the following is a specification.

This invention relates to a valve primarily intended for rock-drills or rock-drilling machines, although it is applicable to othertypes of reciprocating engines. It may be adopted in either the hammer piston type, or the reciprocating bit type of rock-drilling machines.

The object of the invention is to so construct and arrange the valve, valve seats and distribution ports as to obtain a high speed or quick running machine or engine, and one in which the wear and tear on the aforementioned parts will be reduced to a minimum.

The valve is simple in construction, and the arrangement thereof provides for ready aceess'to its several parts for examination, renewal or repair; it is easily and simply adjusted; it is economical in consumption of the motive fluid, for the reason that the cut off is very quick being practically instantaneous; it can be arranged and worked in a very small space, and is suitable for either steam, compressed air or other gaseous motive fluid under suitable pressure.

The engine is preferably provided, with only one exhaust port leading directly through the walls of the cylinder, so that .there is always a pressure on both ends of the piston, and consequently but a small quantity of live air or actuating fluid at Gil 1nitial pressure is required to do the work.

The invention will now be described by aid of the accompanying drawings in which- Figure 1 is a longitudinal section of the cylinder and valve chest, and Fig. 2 is a transverse section of Fig. 1 on line In the accompanying drawing I show the invention applied to a rock-drilling machine.

In the drawing 1 represents the working cylinder of the machine or engine, 2 the piston which'is adapted'to reciprocate'in the cylinder 1, and 3 the piston rod .to which at the forward end the drill bit or steel is attached in any ordinary or suitable manner. The piston 2 is provided with annular re- Tcesses 4 for the reception of any s itable ball or sphere.

form of packing. Although I do not show them it is. well understood that the ends of the cylinder 1 are closed by means of a back cover and front head or their equivalent.

5 represents the exhaust port. It is shown comprising three holes to provide for ready egress of the fluid. The exhaust port 5 is preferably positioned,somewhat forward of the center of the stroke of piston 2, so that the actuating fluid at initial pressure is admitted to the rear end of the cylinder on the forward and working stroke of the machine longer than to the forward end of the cylinder on the backward and idle stroke, or so that said port is uncovered 'bypiston 2 earlier in the back and idle stroke than in the forward stroke.

It will be understood that once exhaust port is overrun by the piston 2 in either direction, the fluid contained within the cylinder is compressed during the remaining portion of the stroke. This compression is utilized to reverse the valve.

(3 represents the valve chest which may as shown be cast or otherwise constructed integral with cylinder 1. Valve chest 6 is bored outas indicated at 7 in a direction parallel with the longitudinal axis of cylinder 1. It is also constructed with an aperture 8-which may as shown be provided with a screw-thread for making connection in any ordinary or convenient manner with the actuating fluid supply pipe-communicating with the bore 7 at the center.

In the bore '7 are formed two annular recesses 9 which form between them a circuback and front induction ports communicating at the one end with the bore 7 and with opposite ends of the bore of working cylinder 1 at the other end. The outer ends of the bore 7 of the valve chest 6 are pro violed with internal screw-threads l3.

Into the interiorly threaded outer ends of the bore 7 are screwed plugs or hollow cylindrical pieces 14 which are open at their inner ends and closed at their outer ends. The outer ends of plugs 14 are preferably constructed with hexagonal or other suitable polygonal heads for screwing them into or out of the valve chest 6. plugs lat are beveled off on' the inside as indicated at 15 toform the valve seats.

10 is the valve which is in the form of a seats 15 in the projection 10 which consti- It moves between the valve The inner ends of supply and opens lIiCl'LlCtlOZIPOli] ll fullyto "seats, and means for adjusting said members relative to one another and means for secura valve chest having bore and an inlet the a in each oi the plugs ,lis termed a ringof holes 1'? which ror acing the interior of the plug in communication with its Ac 'ording to the position 14: is screwed one or tion port.

The which passes between the valve seats 15 and enters the interior of l free to pass byway of holes 17 and iouction ports ll, 12, to opposite ends r g cylinder 1.

l8 are holes in valve casing 6 to. retain or lock plug i in correct position after adjustment of the valve seats 15. V it will 'he noted that the travel or move-' ment of the valve 16 between the valve seats 15 is very short,

in the drawing valve 16 is shown in its central position. It will however be apparent that, assuming the piston is traveling in the direction indicated by the arrow in Fig. i, valve 16 would then been the left hand 15 closing indo tion port 11 to motive fluid supply and opening induction port 12 to said supply move piston 2 through its rearward stroke. lihcn piston 52 closes exl'iaustiport 5 1 1e ll '1 at the rear of said piston hot and compressed, and when piston oveiiuns said exhaust port 5 I and places cylinder 1 at the-front of said piston open to exhaust, the pressure falls in the cylinder at the front of the piston, ininductiou port 12 and its plug 1%. The fluid compressed at the rear of piston 2 then eases. the valve oil". its seat and the motive fluid which is then admitted. between the valve and said throws thovalve over and closes the induction port 12 to motive fluid of w kin mall setscrews screwed through-e said supply which thereupon impcls the'piston through its forward and worl-zing stroke. Vi hat l claim as my invention and desire to protect oy Letters Patent is 'i. A valve of the class described comprising a ball or sphere and oppositely disposed hollow members providing annular valve relative to one another.

Jifvalvc of the class desc'ribed comprising a ball or spherc'and oppositely disposed hollow members providing annular valve seats, means for adjusting said members ing'said memhcrs'in their adjusted positions.

A .valve of tne"olnss described comprisfor the motive fluid communicating with ing a valve chest having a bore and a' central inlet for the motive fluid communicating with said'bore and two recesses in the bore, a ball or sphere located in the bore opposite the inlet and in aprojection formed between the aforesaid recesses, the said projection forming-a guide for it, two hollow plugs open at their inner ends and screwed into the bore, said plugs being beveled oil on the inside at their inner ends to form oppositely disposed valve seats, said plugs having passages through which the motive fluid can pass from their interiors and means for securine the plugs in their adjusted positions.

' 5. K valve of the class described, comprising a valve chest having a longitudinal bore, a transverse inletfor the motive fluid leading into said bore and two annular recesses in the bore at opposite sides of the inlet, a.

ballor sphere arranged in the bore opposite the inlet and adapted to move in a guiding projection formed between the recesses aforesaid, two hollow plugs open at their .nner

ends provided with exterior screw threads,

and having polygonal heads for screwing them into or out of the valve chest, said plugs being beveled 03 on theinside at their inner and open ends to form oppositely disposed seats for 'the valve, and having passages through Which the motive fluid canpass from their interiors and set screws screwed into the valve chest and en a in the 3111 5 b b b b for retaining the latter in position after adjustment. I 6. In a valve of the class described, in combination the valve chest (6) having the bore 7) screw threaded at the ends (l3),

the inlet (8) and the recesses (9) forming the projection (10) the ball or sphere (l6) movable in the projection (10) and opposite inlet (8) the plugs (14) scrcwd into the bore (7) having bevels (15) which con-.

stitute seatings for valve (16) and passages ('17) which serve as. outlets for the fluid, and set screws (18) for retaining plugs (14%) in position after adjustment, as set forth.

a 7. In combination, a working cylinder and a valve chest, the former having induct-ion ports leading from its ends to the valve chest and an exhaust port so positioned that it is uncovered by the piston earlier in the back stroke than in the forward stroke, a piston reciprocally arranged inside the cyli der, the valve chest having a bore parallel with the axis of the cvlindeig'and a central valve chest bore, two plugs screwed into the fluid inlet communicating with said bore, the bore having at its outer ends internal screw threads, and two annular recesses on opposite sides of the inlet, a ball or sphere positioned in the bore and guided by the projection formed by the recesses in the ends of the valve chest bore, said plugs being closed at theifouter ends and formed with polygonal heads for screwing :hem into or out of the bore and open inner posing valve seats, and a plurality of holes for placing the interiors of said plugs n1 communication with their corresponding ing duction ports, said plugs being so arranged that the motive fluid is able to pass from the recesses into the interiors of the plugs all around the valve, and set screws screwed into the chest into engagement with the plugs for retaining the latter in position after adjustment, as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JAMES GARVIE. 

